Purpose of the languages selector in the Python Console
Well, Blender has lots of submenus and options that serve no apparent purpose, so...

Anyway, Blender source code is managed by the Git version-control system which maintains a history of changes as a series of "commits".  In this case, the commit that added this menu is documented as follows:

commit ddeb9f8e24da6076ed76be1573cc152def5751ae
Author: Campbell Barton &lt;ideasman42@gmail.com&gt;
Date:   Fri Nov 6 23:53:40 2009 +0000

    - added console language type
    - separated python console from the interactive console
    - added shell console type (simple example)
    - console types are autodetected and can be selected in the menu


So, a decade ago, one of the lead Blender developers thought that having support for multiple console languages might be useful.

There's still some dead code around, so you can enter the following in a Python Console to get a Bash shell:

&gt;&gt;&gt; bpy.context.space_data.language='shell'
&gt;&gt;&gt; bpy.ops.console.language()
/bin/sh: 1: Syntax error: Bad function name
/u/buhr$


After this, "Python" and "Shell" will appear in the View->Language menu, and you can toggle between them.  Have fun!